Airplane flap with slot controller



c. H. GRANT AIRPLANE FLAP WITH SLOT CONTROLLER June 12, 1951 3 Sheets-Sheet 1 Filed April 9, 1945 INVENTOR cflmlw 4/- M June 12, 1951 c. H. GRANT AIRPLANE FLAP wrm SLOT CONTROLLER 3 Sheets-Sheet 2 Filed April 9, 1945 INVENTOR M UM 5TTORNEY$ June 12, 1951 c, H, RAN 2,556,326

AIRPLANE FLAP WITH SLOT CONTROLLER Filed April 9, 1945 5 Sheets-Sheet 3 INVENTOR Mum TTORNEYS Patented June 12, 1951 UNITED STATES PATENT: OFFICE AIRPLANE FLAP WITH SLOT ooN'monnnn Charles Grant, New Rochelle, Y. Application April 9, 1945, Serial No. 587,302

This invention relates to airplane flaps and to apparatus for controlling the slot between a flap and the fixed or rigid portion of the wing to which the flap is connected.

It is known that greater lift can be obtained by the use of multi-segment flaps in place of the single flaps that have been used. Practical difliculties of obtaining sufficient strength and rigidity without excessive weight, in constructions that require the hinging of one or more flaps to other flaps that are themselves hinged to the rigid portion of the wing, have discouraged the commercial use of multi-segment flaps.

One object of this invention is to obtain the increased lift that results from the use of multisegment or multi-slotted flaps, but Without the use of articulated sections.

Another object of the invention is to 'provide an improved slot controller thatdivides the airstream through the slot in such a way that greater deflection of the flap is possible before the air flow breaks away from the top surface of the wing.

In accordance with one feature of the invention a deflector section located in the slot between the rigid wing portion and the flap moves as the flap is depressed and maintains two slots into which the airflow divides, the width of the slots decreasing progressively in cross section toward their upper ends to increase the velocity of the air streams. The slot at the rearward end of the deflector section is lower than the slot at the forward end so as to change the direction of the air stream over the wing at a pluralityof different locations instead of with a single break in direction of flow as is the case with single flap constructions of the prior art. It may be said, therefore, that another object of the invention is to obtain the effect of a multi-segment flap by means of an auxiliary section located between the rigid forward portion of a wing and a flap that is hinged directly to the rigid portion.

One feature of the invention relates to a construction in which a slot between the flap and the forward section of the wing is equipped with a slot controller that is itself slotted so that the rearward portion of the slot controller serves as an auxiliary wing section.

One of the outstanding advantages of the construction of this invention is that the combined length of the flap and auxiliary deflector section is less than the length of a multi-section flap capable of producing a comparable lift. This makes it possible to locate the rear spar of the 7 Claims. (Cl. 244-42) 1 rigid portion of" the wing further aft with the result that resisting moments of the rigid portion are greater and the rear spar does not need to be as strong or heavy to withstand the pitching moments that cause torsional reactions in. the wings.

Construction is also. lighter as pivotal connections are grouped close together and link con-.

- motions are shorter and lighter.

This application is 'a' companion of my copending application Serial No. 587,301, filed April9, 1945.

Other objects, features andadvantages ofv the 1 invention will appearas the description proceeds.

In the drawings, forming a part hereof, in

which like reference characters indicate corresponding parts in all the views, I V

Figure 1 is a top plan View of a portion of an airplane wing partly broken away to illustrate the construction of the invention.

Figures 2 and 3 are enlarged fragmentary views, taken along the section line 22 of Fig-.

auxiliary deflector l3 that is located in the space between the forward portion II and the flap l2, and that comprises part of the slot controller means.

The rigid section II of the wing has a rear spar l5 to which hinge plates [6 are connected at spaced points along the length of the spar. These hinge plates are arranged in pairs, and the plates of each pair converge rearwardly to provide lateral bracing in a manner well understood in the art.

There are fiap supports l8 extending downward from the forward end of the flap [2. These supports I8 are connected with the hinge plates I6 by pins l9. It will be apparent that this construction provides a flap that is hinged directly to the rigid portion of the wing. The expression hinged directly is used herein to designate any construction in which a plate or bracket that forms an integral part of the flap is connected by a pivot to a bracket plate or other element that forms an integral part of the rigid portion of the wing. The construction distinguishes from those flap structures in which the flap, or:

some portion of it; is hinged to a section of the includes an airfoil I!) hav- :ing a rigid forwardportion II, a flap l2 and an wing that is itself hinged to the rigid portion at another location.

The deflector section I3 extends for substantially the full spanwise width of the flap I2 and is carried on brackets 2I that are connected by pivot pins 22 to the hinge plates I6. The rearward end of the bracket 2| is connected with the flap I2 by a link 24, and the forward end of the bracket 2| is connected by a link 25 to slot controller means 26. The link 24 causes the deflector section I3 to move in coordination with the flap I2 as the latter is deflected, and this link 24 holds the deflector section I3 in position against the pressure of air flowing through the slot between the flap I2 and the forward section of the wing. There are preferably links 24 and 25 at each of the brackets 2I, and the deflector section I3 has a bracket 2I connecting it with the forward wing portion at every pair of hinge plates I6.

The slot controller means shown in the illustration is made in several parts. It has a lower element comprising a door 28 that turns about a pivot 29 that is supported from the rear spar I by lugs 3!]. A spring 32 urges the door 28 into the raised position shown in Figure 2.

The upper portion of the slot controller includes va section 34 that is hinged to the rigid portion of the wing by pivots 35 located at spaced regions along the spanwise extent of the slot controller.

As the flap I2 is depressed, the link 24 pulls the deflector section I3 rearwardly about its pivot pins 22, and the forward end of the bracket 2I pushes the link 25 upward and causes the portion 34 of the slot controller to rock clockwise about its pivots 35 so as to open the slot between the flap and the rigid portion of the wing. As the upper portion 34 of the slot controller moves into an open position, the end of the door 28 slides across the lower side of this upper portion 34 and permits the door to turn under influence of the spring 32 into the position shown in Figure 2.

Motion is imparted to the flap I2 by a mechanical or hydraulic means 38. This means includes a cylinder 39 which is pivotally connected to the rear spar I5 by lugs 40 and .a pin 4|. The cylinder 39 has a piston rod 43 connected by a pin 44 to one of the flap supports I8. Unless the flap I2 is a very long one, cylinder 39 is sufficient to operate the flap.

When the flap is raised, the parts are in the positions shown in Figure 3. The slot between the flap and the rigid forward portion of the wing is closed at the bottom by the slot controller parts 26 and 28, and the upper end of the slot is closed by the deflector I3 which comprises an auxiliary wing section between the flap I2 and the forward portion II of the wing.

As the flap I2 is deflected, it .moves rearwardly because the pins I-9 that comprise the center about which it rotates are located some distance below the flap. This rearward movement of the flap I2 opens the slot between the wing section and the flap. The slot controller portion 26 moves forward and causes an extremely wide opening between the flap I2 and the rigid wing section II. The deflector section I3 is located near the upper end of the slot and is shaped and positioned to divide the upper end of the opening into two slots 46 and 41. Both of these slots are of decreasing cross section toward their upper ends so that the velocity of the air increases as it approaches the upper surface of the wing.

The exits of these slots 46 and 41 open rearwardly and the slot 41 is located some distance behind and at a region somewhat lower than the slot 45. This relation of the slots 46 and 4! permits the direction of the air flow across the top surface of the wing to change at spaced regions so that the change is less abrupt than is the case with conventional designs having a single flap. The slot construction obtained with this invention permits the flap I2 to be deflected further than would otherwise be possible without breaking the .air flow over the top surface of the wing. It is thus possible to obtain greater lift than with conventional wings having a single flap. Working fluid for the hydraulic cylinder 38 (a worm and gear mechanism may also be used) is supplied from conventional control mechanism such as ordinarily used for operating the flaps of an airplane.

The construction illustrated in Figure 3 locates the leading edge of the flap I2 comparatively close to the rear spar I5 of the rigid wing sec-.

tion. The structure can be designed to locate the flap even closer to the rear spar I5. This has the advantage of making the flap section of the wing short, and the construction shown locates the rear spar at a point corresponding to 60% to of the chord. The greater spacing between the front and rear spars of the forward wing section increases the resisting moments and makes it possible for a lighter rear spar to withstand the pitching moments that cause tortional reactions in the wings.

Another advantage of the construction illus-.

trated is that the slot controller opens progressively as the flap is deflected and makes it possible to obtain the advantages of the new slot construction, slot contours being smooth and unbroken for all angles of deflection of the flap.

Figures i and 5 show a modified construction in which a slotted slot controller is used. This slot controller includes a lower section 5i and an upper section 52. These sections 5| and 52 are connected together at their ends by connectors 53 which correspond to the brackets 2i of the construction shown in Figures 2 and 3. If the slot controller is very long, other connectors 53 are used. at locations intermediate the ends of the slot controller in order to obtain the requisite stiffness. The upper section 52 corresponds to the deflector I3 of the construction shown in Fig- 7 ures 2 and 3, and serves the same purpose.

The lower section 5I closes a portion of the lower end of the slot when the flap I2 is in raised position. Agate 55 is connected to the rear spar I5 by a hinge 57. This gate is held against the bottom of the lower section 5| by a spring 55 tensioned between the gate 56 and a lug 60 on the rear spar I5. Except for the difference in shape, the gate 56 and its operating spring are I the same as the gate 28 and corresponding parts in the construction of Figures 2 and 3.

By using a wall 62 rearward of the spar I5 and curved about the axis of the pin 22 as a center, the space ahead of the lower section 5! can be closed against the flow of air without using a gate 58. If the gate 56 is not used, the lower end of the slot controller is extended forward closer to the spar I5, but some space must be left to permit movement of the slot controller.

Although the drawings show the slot controller connected to the hinge plates it which are an integral part of the forward section II of the wing, it will be understood that the, slot controller can be supported from the flap, instead of from the forward portion of the wing, if appropriate changes are made in the operating links, (the restraining link 24 being attached to the rigid forward wing portion).

The preferred embodiments of the invention have been illustrated and described, but changes and modifications can be made, and some features of the invention can be used without others comprises a secondary pivot connection on said wing and on which the deflector is movable chordwise with respect to both the rigid section and the flap, said deflector being within the wing profile and forming a continuation of the upper 1 surface of the wing when the flap is in raised position, mechanism that moves the flap and the deflector in coordinated relation with one another, and that moves the deflector on said secondary pivot into position to open a slot between the rigid-section and the deflector and a second slot between the deflector and the flap with the upper end of the second slot at a lower level than the upper end of the first slot, said deflector being of limited depth and terminating at a region between the first and second slots at a substantial distance above the bottom of the wing profile that air enters the wing through a single slot ahead of the depressed flap and below the de-- flector.

2. In an aircraft wing having a rigid section, a flap spaced rearwardly from the forward section and hinged to the forward section;

by a pivot about which the flap moves rearwardly and downwardly as the flap is depressed, and a deflector located between the rigid section and the flap and closing the space between the rigid section and the flap when the flap is in a raised position, the improvement that comprises a secondary pivot connection on said wing and on" which the deflector is movable chordwise with respect to both the rigid section and the flap, said deflector being within the wing profile and forming a continuation of the upper surface of the wing when the flap is in raised position, mechanism that moves the flap and the deflector in coordinated relation with one another, and that moves the deflector on said secondary pivot into position to open a slot between the rigid section and the deflector and a second slot between the deflector and the flap with the upper end of the second slot at a lower level than the upper end of the first slot, said deflector including a spanwise extending body of airfoil section having .a limited depth substantially less than forward A the depth of the wing profile at the region where r the deflector is located, and said deflector body having its leading edge located substantially above the chordwise center plane of the wing when the flap is depressed so that a stream of air enters the wing through a single slot ahead of the depressed flap and below the deflector and said stream of air is divided by the deflector only after the stream is in the upper half of the wing and approaching the upper surface of said wing.

3. In an aircraft wing having a rigid forward section, a flap spaced rearwardly from the forward section and connected directly to the forward section by a pivot about which the flap rotates rearwardly and downwardly as the flap is depressed, and a deflector located between the rigid section and the flap and closing the space between the rigid section and the flap when the flap is in a raised position, the improvement that comprises a secondary ipivot connection on said wing and on which the deflector is movable chordwise with respect to both the rigid section and the flap, said deflector being within the wing profile and forming a continuation of the upper surface of the wing when the flap is in raised position, mechanism that moves the flap and the deflector in coordinated relation with one another, and that moves the deflector on said secondary pivot into position to open a slot between the rigid section and the deflector and a second slot between the deflector and the flap with the upper end of the second slot at a lower level than the upper end of the first slot, said deflector including a spanwise extending body of airfoil section having a limited depth substantially less than the depth of the wing profile at the region where the deflector is located, and said deflector.

body having its leading edge located substantially above the chordwise center plane of the wing when the flap is depressed so that a stream of air enters the wing through a single slot ahead of the depressed flap and below the deflector and said stream of air is divided by the deflector only after the stream is in the upper half of the wing and approaching the upper surface of said wing.

4. In an aircraft wing having a rigid forward section, a flap spaced rearwardly from the forward section and hinged to the forward section by a pivot about which the flap moves rearwardly and downwardly as the flap is depressed, a deflector located between the rigid section and the flap and closing the space between the rigid section and the flap at the top of the wing profile when the flap is in a raised position, and a gate closing the space at the bottom of the wing profile when the flap is in its raised position, the improvement that comprises a pivot connection on said wing and on which the deflector element is movable chordwise with respect to both the rigid section and the flap, said deflector element being within the wing profile and forming a continuation of the upper surface of the wing when the flap is in raised position, and said gate being within the wing profile and forming a continuation of the lower surface of the wing when the flap is in raised position, mechanism that moves the deflector into position to open a slot between the rigid section and the deflector and a second slot between the deflector and the flap with the upper end of the second slot at a lower level than the upper end of the first slot, said deflector element being of limited depth and terminating at a region between the first and second slots at a substantial distance above the bottom of the wing profile so that air enters the wing through a single slot ahead of the depressed flap and below the deflector element, and mechanism that moves the flap, deflector element and gate in co ordinated relation with one another.

5. In an aircraft wing having a rigid forward section, a fiap hinged to the forward section and that can be raised and depressed and that is 7 1 spaced from the rigid section in all positions, a deflector element between the rigid section and the flap within the wing profile and forming a continuation of the upper wing surface, and a gate between the rigid section and the flap within the wing profile and forming a continuation of the lower wing surface, the improvement that comprises a pivot connecting the deflector element to the wing and on which said deflector element is movable with respect to both the rigid section and the flap, said deflector element being of a length to cover the top of the space between the rigid section and the flap, a pivot connecting the gate to the wing with the gate closing the lower end of the space between the rigid section. and the flap below the deflector element, said gate being movable upward about its pivot to open the lower end of said space, mechanism that moves the deflector into position to open a slot between the rigid section and the deflector and a second slot between the deflector and the flap with the upper end of the second slot at a lower level than the upper end of the first slot, and motion transmitting connections that coordinate the movement of the gate and deflector movement with the raising and depressing movements of the flap.

6. In an aircraft wing having a rigid forward section, a flap hinged to the forward section and that can be raised and depressed and that is spaced from the rigid section in all positions, a deflector element between the rigid section and the flap within the wing proflle and forming a continuation of the upper wing surface, and a gate between the rigid section and the flap within the wing profile and forming a continuation of the lower wing surface, the improvement that comprises a pivot connecting the deflector element to the wing and on which said deflector element is movable with respect to both the rigid section and the flap, said deflector element being of a length to cover the top of the space between the rigid section and the flap, telescoping sections that comprise the gate, separate pivots connecting said sections to the wing with said sections closing the lower end of the space between the rigid section and the flap below the deflector element, the sections of the gate having a telescoping movement with respect to one another which opens the lower end of the space between the rigid section and the flap when the gate sections swing about their pivot connections to the wing, mechanism that moves the deflector into position to open a slot between the rigid section and the deflector and a second slot between the deflector and the flap with the upper end of the second slot at a lower level than the upper end of the first slot, and motion transmitting connections that coordinate the movement of the gate and deflector movement with the raising and depressing movements of the flap.

'7. An aircraft wing comprising a rigid forward section, a flap, connecting elements including. hinge plates rigidly connected with said forward portion and extending rearwardly therefrom,- pivot means connecting the flap directly to the hinge plates that extend from the forward section of the wing for movement between raised and depressed positions, said connecting elements being of such chordwise length that there is a substantial space between the flap and the rigid section of the wing, a gate comprising telescoping sections connected to the wing and lo cated in position to span the lower end of said space when the flap is in raised position, hinge means on which the gate sections swing into open positions to create a slot forward 'of the flap so that air can enter said slot, when the flap is depressed, a deflector in the space above the gate within the upper profile of the wing in posi-' tion to close the upper end of the slot when the flap is in a raised position, a pivot connecting the deflector with the wing and on which said deflector is movable with respect to the forward section and the flap as the flap is depressed to divide the upper portion of the slot into two spaced slots, the confronting faces of said slots converging toward the upper ends of the slots to give the slots decreasing width toward their upper ends, connections between the deflector and flap for controlling their relative movement as" the flap is depressed, connections between the gate and the deflector for moving the gate when the deflector turns on its pivot, and operating means for raising and depressing the flap.

CHARLES H. GRANT.

REFERENCES CITED The following references are of record in the,

file of this patent:

UNITED STATES PATENTS Number Name Date 2,271,763 Fowler Feb. 3, 1942 2,276,522 Stauffer Nov. 17, 1942 2,282,516 Gropler et al May 12, 1942 2,289,704 Grant July 12', 1942 FOREIGN PATENTS Number Country Date 519,236 Great Britain Nov. 20, 1940 OTHER REFERENCES Ser. No. 309,655, Bechereau (A. P. 0.), published May 25, 1943. 

